Sawflies are in the same group of insects as bees, ants and wasps (the Hymenoptera). They have caterpillar like larvae that feed on plants and the adults are winged insects that can appear fly-like.

Social pear sawfly has orange caterpillar-like larvae that reach 25mm (1in) in length. The larvae feed on leaves in groups within webbing which can cover entire branches. Most often seen on pear, it will also feed on hawthorn, cherry, medlar, plum and cotoneaster. Hawthorn and cotoneaster can also be affected by caterpillars of the hawthorn webber and porphyry knothorn moth, these have small brown caterpillars and also produce webbing.

The adult is a 14mm (½in) long black winged insect. 

Social pear sawfly is rarely abundant and the presence of this insect can usually be treated as part of the biodiversity a healthy garden supports as it doesn't impact the health of host trees.

• Encourage predators and other natural enemies in the garden such as birds
• If necessary it is possible to control social pear sawfly by pruning out the affected part of the tree and disposing of the larvae